U.S. patent number 6,245,324 [Application Number 09/388,699] was granted by the patent office on 2001-06-12 for antiperspirant material and compositions containing it.
This patent grant is currently assigned to Unilever Home & Personal Care USA, Division of Conopco, Inc.. Invention is credited to Gordon Charles Hough, David Terence Parrott, John Harold Rennie.
United States Patent |
6,245,324 |
Hough , et al. |
June 12, 2001 |
Antiperspirant material and compositions containing it
Abstract
A particulate antiperspirant active material which has been
surface treated with an alkanolamine is described. After surface
treatment, the surface treatment agent is in intimate contact with
the surface or outer layer of the substrate material, that is, the
antiperspirant material may be either deposited on the surface or
at least a fraction of the agent may be absorbed within the outer
layer of the substrate. The resultant particulate material shows a
reduced tendency to separate from a liquid carrier phase containing
a polyglycol ether and a suspending agent.
Inventors: |
Hough; Gordon Charles
(Bebington, GB), Parrott; David Terence (Chicago,
IL), Rennie; John Harold (Chester, GB) |
Assignee: |
Unilever Home & Personal Care
USA, Division of Conopco, Inc. (Chicago, IL)
|
Family
ID: |
10838387 |
Appl.
No.: |
09/388,699 |
Filed: |
September 2, 1999 |
Foreign Application Priority Data
Current U.S.
Class: |
424/65; 424/400;
424/401; 424/66; 424/67; 424/68 |
Current CPC
Class: |
A61K
8/25 (20130101); A61K 8/26 (20130101); A61K
8/28 (20130101); A61K 8/29 (20130101); A61K
8/34 (20130101); A61K 8/41 (20130101); A61K
8/585 (20130101); A61K 8/8111 (20130101); A61K
8/86 (20130101); A61Q 15/00 (20130101); A61K
2800/412 (20130101) |
Current International
Class: |
A61K
8/41 (20060101); A61K 8/34 (20060101); A61K
8/58 (20060101); A61K 8/30 (20060101); A61K
8/19 (20060101); A61K 8/26 (20060101); A61K
8/28 (20060101); A61K 8/25 (20060101); A61K
8/29 (20060101); A61Q 15/00 (20060101); A61K
007/32 (); A61K 007/34 (); A61K 007/36 (); A61K
007/38 (); A61K 007/00 () |
Field of
Search: |
;424/65,66,67,68,400,401 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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22 41 030 |
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Aug 1972 |
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DE |
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24 05 216 |
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Feb 1974 |
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DE |
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0 021 262 |
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Jun 1979 |
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EP |
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0 559 319 |
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Sep 1993 |
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EP |
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0 832 639 |
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Sep 1996 |
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EP |
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1391448 |
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Apr 1975 |
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GB |
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1 602 428 |
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Jun 1977 |
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GB |
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Other References
International Search Report Application No. PCT/EP 99/05613 mailed
Dec. 3, 1999..
|
Primary Examiner: Dodson; Shelley A.
Attorney, Agent or Firm: Boxer; Mathew
Claims
What is claimed is:
1. A particulate antiperspirant material which has been surface
treated with an alkanolamine.
2. An antiperspirant material according to claim 1 wherein the
alkanolamine comprises a C1 to C8 alkanol.
3. An antiperspirant material according to claim 2 wherein the
alkanol is propanol or butanol.
4. An antiperspirant material according to claim 1 wherein the
alkanolamine is a secondary amine.
5. An antiperspirant material according to claim 4 wherein the
alkanolamine is methylpropanolamine.
6. An antiperspirant material according to claim 1 wherein the
particulate material supports from 0.2% to 8% by weight of the
alkanolamine.
7. An antiperspirant material according to claim 6 wherein the
particulate material supports from 0.4% to 2.5% by weight of the
alkanolamine.
8. An antiperspirant material according to claim 1 wherein the
particulate material comprises an astringent compound of aluminium,
zirconium, mixed aluminium/zirconium or titanium.
9. An antiperspirant material according to claim 7 wherein the
astringent compound comprises an aluminium chlorohydrate or an
activated aluminium chlorohydrate.
10. An antiperspirant material according to claim 1 wherein the
material has an average particle size in the range of from 10 to 70
.mu.m.
11. A process for surface treating a particulate antiperspirant
material which comprises bringing the antiperspirant material into
contact with an alkanolamine in a liquid medium and maintaining
contact until at least some alkanolamine is deposited on or
absorbed in the surface of the antiperspirant material.
12. A process according to claim 10 which comprises alkanolamine is
contacted with the antiperspirant material in molten form or in
solution.
13. An antiperspirant composition comprising an antiperspirant
material and a liquid phase comprising a carrier wherein said the
antiperspirant material comprises a particulate antiperspirant
material which has been surface treated with an alkanolamine.
14. A composition according to claim 12 wherein the carrier
comprises a polyglycol ether.
15. A composition according to claim 14 wherein the polyglycol
ether comprises an ether of a polyethylene glycol, a polypropylene
glycol or a polybutylene glycol.
16. A composition according to claim 15 wherein the polyglycol
moiety contains from 5 to 24 glycol units.
17. A composition according to claim 14 wherein the polyglycol
ether comprises polyglycol ether of a C3 to a C8 aliphatic
alcohol.
18. A composition according to claim 17 wherein the alcohol is
propanol or butanol.
19. A composition according to claim 18 wherein the polyglycol
ether comprises a polypropylene glycol butyl ether containing from
10 to 16 polypropylene glycol units.
20. A composition according to claim 14 wherein the polyglycol
ether constitutes from 5 to 95% by weight of the liquid phase.
21. A composition according to claim 14 wherein the polyglycol
ether constitutes from 40 to 60% by weight of the liquid phase.
22. A composition according to claim 14 wherein the polyglycol
ether and the alkanolamine are present in a weight ratio of from
30:1 to 120:1, preferably 45:1:80:1.
23. A composition according to claim 13 wherein the carrier
contains a volatile or a non-volatile silicone oil.
24. A composition according to claim 23 wherein the liquid phase
comprises 20 to 70% and preferably 40 to 70% by weight volatile
silicone oil.
25. A composition according to claim 23 wherein the liquid phase
contains from 0.01 to 0.1% by weight of a non-volatile silicone
oil.
26. A composition according to claim 13 containing a clay or silica
suspending agent.
27. A composition according to claim 26 wherein the suspending
agent comprises from 2 to 6% by weight based on the composition of
a hydrophobically treated clay.
28. A composition according to claim 13 comprising containing one
or more suspension assistants, emollients or fragrances.
29. A composition according to claim 13 wherein the liquid phase
constitutes from 90 to 50%, preferably 75 to 55% by weight and the
particulate antiperspirant constitutes from 10 to 50%, preferably
25 to 45% by weight.
30. A composition according to claim 13 wherein from 95 to 1 parts,
preferably 40 to 5 parts by weight of the composition is contacted
with from 5 to 99 parts and preferably 60 to 95 parts by weight of
a propellant to form an aerosol composition.
31. A composition according to claim 30 wherein from 40 to 5 parts
by weight of the composition is contacted with from 60 to 95 parts
by weight of the propellant to form the aerosol composition.
32. A method of controlling perspiration comprising topically
applying to human skin a composition according to claim 14.
Description
The present invention relates to an antiperspirant material, a
process for its preparation and to antiperspirant compositions
containing it.
TECHNICAL FIELD BACKGROUND AND PRIOR ART
In a significant fraction of antiperspirant compositions, the
active antiperspirant material is present in particulate form. For
ease of dispensation, in many of such compositions, the active
antiperspirant material is suspended or otherwise dispersed in a
liquid carrier phase, often with the assistance of suspension
agents or aids. If the antiperspirant material is not suitably
suspended, there is a risk that it will tend to separate from the
liquid carrier, for example by settling on the bottom of the
container for the composition during storage or between
applications. When the settled material can be readily redispersed
by the user, such as by manual shaking of the applicator before
use, solids settling constitutes a minor inconvenience rather than
a significant problem. However, when the settling produces a
compact layer which is extremely difficult or even impossible to
redisperse manually, the problem attains serious proportions,
because is extremely desirable to avoid or reduce the effective
loss from the formulation of active antiperspirant material.
Self-evidently, loss of active material during storage renders the
composition non-uniform in application, with the risk that for a
fraction of the time that the composition is used, it will be
ineffective or insufficiently effective at controlling perspiration
loss.
It has been found that advantageous skin sensory properties can be
achieved by incorporating a polyglycol ether as at least part of
the liquid phase in an antiperspirant composition. A practical way
of suspending a particulate antiperspirant in a liquid carrier has
comprised the incorporation of a suspending aid, often inorganic
such as a clay. However, it has further been found that when the
carrier comprises a polyglycol ether, the ability of the clay or
like suspending agent to suspend or re-suspend the particulate
antiperspirant material in the carrier liquid is significantly
impaired.
It is known to surface treat particulate inorganic substances in
other fields of activity, specifically pigments and sunscreens, but
for other purposes. Thus, for example, titanium dioxide pigments
are surface treated in GB-A-1602428 with esters or amines and this
affects the rate at which films containing the pigment dry. In
EP-A-0559319, metallic oxide particles, especially titanium dioxide
and zinc oxide particles are surface coated to aid their suspension
in aqueous emulsions. This is not relevant to predominantly
anhydrous compositions of the present invention. Similarly in U.S.
Pat. No. 5,573,753, dispersions of surface treated particulate
titanium oxide and zinc oxide in an aqueous emulsion are described.
In U.S. Pat. No. 4,318,843 (EP-A-0021262) there is described the
surface treatment of inorganic pigments of which TiO.sub.2 is
exemplified in order to improve its gloss and distribution in
lacquer bindings. In U.S. Pat. No. 5,776,440, the effectiveness of
metallic oxide to screen out UV-radiation when applied topically is
enhanced by coated them with a wide range of organic compounds. The
treatment of TiO2 is exemplified.
It is an object of the present invention to ameliorate or overcome
one or more of the problems or disadvantages indicated
hereinabove.
SUMMARY OF THE INVENTION
According to the present invention there is provided a particulate
antiperspirant material which has been surface treated with an
alkanolamine.
According to related aspect of the present invention there is
provided a process for surface treating a particulate
antiperspirant material characterised by bringing the
antiperspirant material into contact with an alkanolamine in a
liquid medium and maintaining contact until at least some
alkanolamine is deposited on or absorbed in the surface of the
antiperspirant material.
By surface treating the particulate antiperspirant material with
the alkanolamine, it has been found that the resultant particulate
material shows a reduced tendency to separate from a liquid carrier
phase containing a polyglycol ether and a suspending agent.
Surface treating and surface treatment herein indicates that the
surface treatment agent is in intimate contact with the surface or
outer layer of the substrate material, i.e. the antiperspirant
material, and may either be deposited on the surface, for example
forming a layer or coating of the treatment agent on the substrate
surface or at least a fraction of the agent may be absorbed within
the outer layer of the substrate.
In a further aspect of the present invention, there is provided an
antiperspirant composition comprising an antiperspirant material
and a liquid phase comprising a carrier characterised in that the
antiperspirant material comprises a particulate antiperspirant
material which has been surface treated with an alkanolamine.
Herein, comprising in the context of a composition indicates that
the composition may contain one or more further ingredients in
addition to those specified within the composition.
DETAILED DESCRIPTION OF THE INVENTION
The invention provides a particulate surface treated antiperspirant
active and antiperspirant compositions containing the same, and
especially compositions containing a polyglycol ether and a
suspending agent.
Antiperspirant Material
The antiperspirant material can comprise any particulate material
which is capable of reducing or preventing perspiration when it is
applied topically to human skin. The present invention is directed
to antiperspirant actives which when applied topically penetrate
the eccrine gland and are subsequently deposited therein, blocking
its duct and preventing egress of sweat. Accordingly, such material
commonly comprises an astringent salt. The antiperspirant often
comprises aluminium, zirconium, mixed aluminium/zirconium salts,
and titanium salts, including both inorganic salts and organic
salts and complexes. Preferred astringent salts include aluminium,
zirconium and aluminium/zirconium halides and halohydrate salts,
such as chlorohydrates. Some especially preferred halohydrate salts
comprise activated aluminium chlorohydrates such as those described
in EP-A-6739 (Unilever NV et al) and other actives are described in
EP-A-28853, the contents of both specifications being incorporated
herein by reference. It will be recognised that metallic oxides
derived from aluminium, zirconium, titanium or zinc are considered
not to be antiperspirants.
Astringent aluminium salts include aluminium chloride and aluminium
halohydrates having the general formula Al.sub.2 (OH).sub.x
Q.sub.y.XH.sub.2 O in which Q represents chlorine, bromine or
iodine, x is from 2 to 5 and x+y=6, x and y being either integers
or non-integers and X being from 0 to 6.
A range of zirconium salts which can be employed in antiperspirant
compositions herein is represented by the following empirical
general formula: ZrO(OH).sub.2n-nz B.sub.z in which z is an integer
or non-integer in the range of from 0.9 to 2.0, n is the valency of
B, 2-nZ is at least 0 and B is selected from the group consisting
of halides, including chloride, sulphamate, sulphate and mixtures
thereof.
It will be recognised that the above-identified formulae for
aluminium and zirconium salts are greatly simplified and encompass
compounds having co-ordinated and/or bound water in various
quantities as well as polymeric species and mixtures and
complexes.
Antiperspirant complexes based on the above-mentioned astringent
salts are known and employable in the present invention. By way of
example, complexes of aluminium, zirconium and aminoacids such as
glycine are disclosed in U.S. Pat. No. 3,792,068 (Luedders et al).
Certain of those complexes or complexes with related structures are
commonly called ZAG in the literature. One desirable class of
complexes which exhibit structure like ZAG comprise aluminium
chlorohydrate, including that satisfying the formula Al(OH).sub.5
Cl.2H.sub.2 O complexed with aminoacids or other complexing agents.
A preferred class of zirconium-based complexes which exhibit
structures like ZAG comprise zirconylchlorohydrate of empirical
formula ZrO(OH).sub.2-a Cl.sub.2.nH.sub.2 O in which a is a
non-integer in the range of from 1.5 to 1.87 and n is from 1 to 7
complexed with amino acids or other complexing agents. Activated
ZAG complexes can be employed as antiperspirant active in the
present invention, such as the materials disclosed in U.S. Pat. No.
5,486,347 (Callaghan et al).
Other actives which can be contemplated for employment as
appropriate in compositions produced and/or dispensed in accordance
with the present invention comprise particulate titanium salts such
as hydroxycarboxylates, e.g. citrate or lacteate.
Particularly when the antiperspirant salt is intended to be applied
in an aerosol, it is preferable to employ a zirconium-free salt,
such as an aluminium salt or possibly a titanium salt, including
especially aluminium chlorohydrates (ACH) and activated aluminium
chlorohydrates (AACH).
The particle size of antiperspirant salts employed herein often
falls within the range of 1 to 200 micrometers. In many desirable
formulations, and especially for application by an aerosol, the
mean particle size of the antiperspirant salt falls within the
range of from 5 to 50 .mu.m and especially from 15 to 30 .mu.m.
Alkanolamine
The alkanolamine can comprise an aliphatic compound containing both
an amine and an hydroxyl function. It desirably has a low molecular
weight, for example containing up to 12 carbon atoms, which can
include a linear or branched alkyl group. The alkanol moiety
preferably comprises a C.sub.3 or C.sub.4 alkyl group, as in
hydroxypropylamine or hydroxybutylamine. The amine can be primary,
secondary or tertiary. All of the amine substituents can comprise
alkanol substituents, or in secondary amines or in tertiary amines,
respectively one or either one or two of the substituents can
comprise a an alkyl group, such as C.sub.1 to C.sub.4. Examples of
a primary amine include propanolamine, secondary amine include
methyl propanolamine and examples of a tertiary amine include
triisopropanolamine. In many instances, the alkanolamine comprises
a single amine and in other instances comprises from 1 to 3
hydroxyl groups, though normally not more than two hydroxyl
substituents in any particular alkanol group. A mixture of two or
more of such alkanolamines can also be employed. The antiperspirant
material can conveniently be surface treated by bringing it into
contact with the alkanolamine in fluid form. For example the
alkanolamine can be heated to above its melting point, where
necessary, or dissolved in a suitable solvent. The solvent can
comprise a hydrophobic liquid such as a silicone oil or a
hydrocarbon oil. The antiperspirant and alkanolamine are desirably
left in contact until a desired weight of the alkanolamine has been
retained by the antiperspirant, normally as a surface layer on or
coating of the antiperspirant or absorbed within the outer layer of
the antiperspirant. Where the alkanolamine is applied to the
antiperspirant in solution, the solution can, if desired, be
allowed to remain permanently in contact with the antiperspirant,
instead of being separated when the antiperspirant carried a
desired amount of the alkanolamine, in which case the solvent for
the alkanolamine subsequently functions as a liquid carrier or a
component thereof in an antiperspirant composition. In such
compositions, a fraction of the alkanolamine may remain within the
liquid carrier.
It will be recognised that the surface treatment of the
antiperspirant solid can be carried out as a separate step, for
example before the antiperspirant active is incorporated into an
antiperspirant composition, or can form in situ provided that the
composition contains both the alkanolamine and antiperspirant
active in a fluid medium that enables them to come into contact
with each other.
The antiperspirant material is normally brought into contact with
from 0.2 to 8% by weight of the alkanolamine, and in many instances
the proportion of alkanolamine is selected in the range of from 0.4
to 2.5% by weight, based on the weight of the antiperspirant. An
especially convenient range can be from 0.75 to 1.5% by weight of
alkanolamine based on the antiperspirant.
The surface treated antiperspirant material is frequently
incorporated in a composition comprising a liquid carrier. The
proportion of antiperspirant material is normally calculated by
weight on an anhydrous salt basis, i.e. excluding the weight of any
hydrated water or complexing agent that may also be present and
excluding the weight of any surface treatment.
Liquid Carrier
In an important aspect of the present invention, the liquid carrier
comprises a polyglycol ether, the latter preferably constituting
from 5 to 95% by weight of the liquid phase, particularly from 30
to 75% and especially from 40 to 60%. Such a composition represents
a convenient base composition which is capable of being employed by
itself or of serving as a base composition to which further
constituents can be added, for example to create an aerosol
composition. The presence of the polyglycol ether imparts
advantageous emollient properties, and can lower visible deposits
when the composition is topically applied to human skin.
The polyglycol ether usually is derived from a low molecular weight
glycol, frequently a C.sub.2 to C.sub.4 glycol, such as from
ethylene, propylene or butylene glycol and is especially a
polypropylene glycol ether. The polyglycol moiety desirably
contains from 5 to 24 glycol units and in a number of preferred
ethers contains from 10 to 16 glycol units, especially 10 to 16
propylene glycol units. The ether moiety is preferably aliphatic,
derivable from a low molecular weight aliphatic alcohol and
especially an alkanol containing up to 8 carbons, particularly 3 to
8 carbons. The alkanol is frequently propanol or butanol.
Polypropylene glycol butyl ethers in which the polyglycol moiety
contains 10 to 16 propylene glycol units, e.g. 13 or 14, are
particularly suitable.
In practice, it is desirable to select the proportions of the
polyglycol ether and the alkanolamine, both as described
hereinbefore, in the composition to fall within a weight ratio of
20:1 to 150:1, particularly 30:1 to 120:1 and preferably 45:1 to
80:1.
By selecting the relative proportions of polyglycol ether and
alkanolamine within the above-identified ratio ranges and
especially within the preferable range, it is possible to improve
the suspension of the particulate antiperspirant material in
polyglycol ether carrier fluids in the presence of a suspending
agent. In the absence of the alkanolamine, there is a tendency in
such compositions for layers of the particulate material to settle
out during storage which are extremely difficult or impossible to
redisperse by manual shaking. By incorporating the alkanolamine,
such as by bringing it into intimate contact with the
antiperspirant, it is possible to inhibit or substantially
eliminate the tendency of such very poorly redispersible layers to
form. To the extent that some or all of the particulate material
does settle out, it can be more readily redispersed, for example by
manual shaking, when the alkanolamine is incorporated in
composition.
It will be recognised that the alkanolamine can be present in the
composition as a surface treatment on the antiperspirant material
and also that a fraction of it can remain in solution in the liquid
carrier.
In a number of particularly desired embodiments of the present
invention, there is provided an antiperspirant composition
comprising a particulate antiperspirant material, an alkanolamine a
liquid carrier comprising a polyglycol ether and a suspending
agent.
Suspending Agent
In such a composition, the suspending agent is suitably inorganic,
and is particularly a clay or a silica. The clay is often a
montmorillonite, and advantageously can have been surface treated
with an organic material such as an amine to render it hydrophobic.
Examples of montmorillonites include bentonites, hectorites and
colloidal magnesium aluminium silicates. Particularly suitable
surface treated clays comprise surface treated bentonites which are
available under the trademark Bentone from Rheox, such as Bentone
27, Bentone 34 Bentone 38 and Bentone LT. Suitable silicas include
fumed silicas and particularly those of very fine particle size,
such as those available under the trademarks Cab-o-sil and AEROSIL.
It is especially desirable that the suspension agent is a
hydrophobically surface treated clay.
The suspending agent is often incorporated in an amount of from 0.1
to 15% by weight of the compositions described herein and in
particular in an amount of from 3 to 10% of base compositions, i.e.
compositions comprising solely antiperspirant active, carrier
liquid, alkanolamine and suspending agent before being formulated
with for example a propellant to produce an aerosol. In preferred
formulations according to the present invention, the weight ratio
of antiperspirant to suspending agent is often selected in the
range of from 2.5:1 to 20:1.
Other Constituents
The liquid carrier is normally anhydrous, that is to say does not
contain any free water and particularly does not contain an aqueous
phase. In practice, this means that formulations containing such
carriers are anhydrous. In addition to the polyglycol ether, the
liquid carrier can additionally comprise one or more hydrophobic
fluids, including silicone oils, and liquid hydrocarbons. The
liquid carrier often comprises from 5 to 80% by weight of the
composition. Where the composition constitutes a base composition
which is intended to be augmented with propellant to form an
aerosol composition, the proportion of liquid carrier is
particularly from 30 to 70% by weight of the base composition. The
liquid carrier or mixture of carriers often constitutes 70 to 99%
and particularly 80 to 95% of the liquid phase in the base
composition, recognising that liquid constituents which are
incorporated as emollients also function as carriers. The ratio of
polyglycol ether to the total of other carriers in the compositions
is often selected in the range of from 10:1 to 1:10, and in many
preferred compositions is in the range of 2:1:1:2.
Silicone oils are preferred constituents of the composition and
such oils employable herein are normally chosen from polysiloxanes
and particularly polyalkylsiloxanes, or from silicone glycols. The
oils can be either volatile or non-volatile or a mixture of both,
but preferably volatile oils constitute the major proportion of
silicone oils.
Volatile silicones are often chosen from cyclic polysiloxanes of
formula --[--SiRR'--].sub.n -- in which R and R' represent an
alkyl, preferably a methyl group and n is from 3 to 8 and
especially 4 or 5, otherwise referred to as cyclomethicones. Other
suitable volatile silicones can be selected from low molecular
weight linear polysiloxanes of formula SiRR'R"--[--SiRR'--].sub.m
--SiRR'R" in which R R' and R" each represent an alkyl, preferably
a methyl group and m is from 1 to 7 and especially 2 or 3. The
volatile silicone oils generally have a viscosity of from about 1
to 10 centistokes at 25.degree. C. Examples of volatile silicones
are Dow Corning 225, 244, 245, 344, 345, 1732, 5732, 5750, (all
available from the Dow Corning Corp.) and Silicone GE7207, GE7158,
SF1202, SF1173, SF-96 and SF-1066 (all available from General
Electric Co [USA]).
Non-volatile silicone oils which are suitable for incorporation in
compositions herein can comprise polyalkylsiloxanes,
polyalkarylsiloxanes or polyether siloxane copolymers, typically
having a viscosity of above 10 centistokes at 25.degree. C. Many
non-volatile silicone oils have a viscosity often up to about 2000
centistokes, and others have a still higher viscosity, such as up
to about 10.sup.6 to 5.times.10.sup.6 centistokes. Examples of
suitable non-volatile polyalkylsiloxanes are available from Dow
Corning under the 200 series. Suitable polyalkarylsiloxanes
comprise polymethylphenylsiloxanes having a viscosity of from about
15 to 65 censtistoke at 25.degree. C., such as those available from
Dow Corning as 556 fluid. Suitable polyether siloxanes comprise
dimethylpolyoxyalkalene ether copolymers (dimethicone copolymers)
which often have a viscosity of from 1200 to 1500 censtistoke at
25.degree. C., such as a polysiloxane ethylene glycol ether
copolymer. Yet other suitable non-volatile silicone oils comprise
or contain dimethicone/alcohol polymers (dimethiconols).
The liquid carrier can comprise, if desired a liquid hydrocarbon,
such as a mineral oil, paraffin oils, petrolatum or hydrocarbon
oils.
The liquid phase of compositions herein can additionally comprise
other liquid emollients, such as liquid esters often containing
from about 12 to 25 carbons which contain a long chain (usually
containing at least 12 carbons) and short chain alkyl group
(usually containing from 2 to 6 carbons), derivable from an acid
and alcohol, or vice versa, such as isopropyl myristate or
palmitate. Other suitable esters comprise short chain alkyl esters
of aryl di or tri carboxylic acids, such as diethyl or dibutyl
phthalate. Other liquid emollients include liquid fatty alcohols,
often having a molecular weight of from about 200 to 350, such as
octyldodecanol or isocetyl alcohol.
The composition can additionally comprise one or more suspension
assistants, for example propylene carbonate, and in an amount of
from 0 to 50% by weight of the suspension agent. Other optional
constituents of the composition comprise an antioxidant or
preservative, which sometimes comprises from 0 to 0.5%,
particularly from 0.01 to 0.15% by weight of the composition.
An important, though optional, constituent of many antiperspirant
compositions according to the present invention is a fragrance. The
fragrance can be incorporated in oil-soluble form and/or be
encapsulated. In many of the invention compositions, the fragrance
comprises 0.1 to 3% by weight. In base formulations, i.e. those
intended to be diluted e.g. with liquified propellant, the
fragrance can often represent a relatively high proportion, such as
from 1.5 to 8%.
Additional optional constituents of the composition can comprise a
particulate filler, preferably impalpable, such as talc or a
microfine starch or starch succinate derivative (Dry Flo.TM.) or a
very fine particulate polyethylene (Acumist.TM.), and conveniently
in an amount of from 0 to 20% of a base composition, and
particularly in dispensed formulations of from 0 to 5%. A further
optional constituent can comprise a microbicide, such as a
bactericide, which in some compositions is incorporated in an
amount of from 0.1 to 1% by weight. Suitable microbicides include
biguanide salts such as available under the trademark Cosmosil.TM.
and chlorinated aromatics, including chlorinated phenyl ethers and
biguanide derivatives, of which materials known as Triclosan,
Triclorban.TM. and Chlorhexidine warrant specific mention.
The antiperspirant compositions described herein can be made by
mixing the constituents, for example using conventional apparatus
for mixing a particulate material with one or more liquids. They
are particularly suited for application via a spray, or by a
roll-on.
Aerosol Formulations
In one especially desirable aspect of the present invention, the
compositions above described are diluted with a propellant to form
an aerosol formulation. The aerosol formulation often comprises
from 40 to 99 parts by weight, and particularly 50 to 95 parts by
weight propellant and the remainder (respectively 60 to 1 and
particularly 50 to 5 parts by weight) the antiperspirant base
composition.
The propellant is normally selected from liquified hydrocarbon or
halogenated hydrocarbon gasses which have a boiling point of below
10.degree. C. and especially those with a boiling point below
0.degree. C. It is especially preferred to employ liquified
hydrocarbon gasses, and especially C.sub.3 to C.sub.6 hydrocarbons,
including propane, isopropane, butane, isobutane, pentane and
isopentane and mixtures of two or more thereof. Preferred
propellants are isobutane, isobutane/isopropane, isobutane/propane
and mixtures of isopropane, isobutane and butane.
Other propellants which can be contemplated include alkyl ethers,
such as dimethyl ether or compressed non-reactive gasses such air,
nitrogen or carbon dioxide.
The aerosol formulation can incorporate, if desired, anticlogging
agents in conventional amounts, in order to prevent of minimise the
occurrence of solid occlusions in the spray nozzle.
The aerosol formulation is usually filled into an aerosol canister
that is capable of withstanding pressures generated by the
formulation, employing conventional filling apparatus and
conditions. The canister can conveniently be a metal canister
commercially available fitted with a dip tube, valve and spray
nozzle through which the formulation is dispensed.
The antiperspirant compositions according to the present invention
can be applied topically to human skin, in order to control
perspiration
Having described the invention in general terms, specific
embodiments thereof are now described in greater detail by way of
example only.
EXAMPLE 1
In this Example, a surface treated particulate antiperspirant
material is obtained by introducing activated aluminium
chlorohydrate (hereinafter AACH) (100 g) which has been obtained by
heating aluminium chlorohydrate having a suitable formula under
suitably controlled conditions, having a particle size of 10 to 70
.mu.m into a vessel equipped with agitation means. Thereafter,
molten methyl propanolamine (1 g) is added and mixed thoroughly
with the AACH for a period of a few minutes. The resultant product
consists of AACH which has been surface treated with methyl
propanolamine.
EXAMPLES 2 TO 8
In each of these Examples, a base composition is obtained which is
suitable for dilution with propellant to form an aerosol
composition employing a conventional method for mixing a
particulate constituent with liquid constituents. The compositions
are as summarised in Table 1 below:
Percent by weight Example No Constituent 2 3 4 5 6 7 8 AACH 40
38.46 10 30.8 40 38.5 ACH 48 hydrophobic clay 7.7 3.9 (Bentone 27)
hydrophobic clay 4 4.8 3.5 4 3.8 (Bentone 38) PPG13 butyl ether 24
20.76 23.07 50 27 24 23.1 (Fluid AP) Methylpropanol-) 0.4 0.44 0.39
0.4 0.4 0.4 0.4 amine (AMP 100) Volatile silicone 28 22 28.2 27.7
(DC245) Volatile silicone 24.23 (DC345) Volatile silicone 29.55
(DC1465) Volatile silicone 34.8 (DC246) Fumed silica 0.4 0.05
(AER-O-SIL 200) Octyldodecanol 1.2 isopropymyristate 0.8 Propylene
carbonater 0.77 Polydecene (Silkflo 364) 1.5 Diethyl phthalate 0.4
Silicone gum (Q2-1501) 0.8 1.5 fragrance 2 4 5.38 5 1.9 2.6 5
The compositions described in Table 1 demonstrated good resistance
to formation of a settled compacted solids layer and a good
capability of settled solids to redisperse when subjected to manual
shaking.
EXAMPLES 9 TO 15
In these Examples, aerosol formulations were obtained by diluting
the base compositions described in Table 1 with a liquified
hydrocarbon propellant using conventional methods. The formulations
were filled into conventional blown aluminium aerosol canisters
fitted with dipstick, flow valve and spray head. The aerosol
formulations are summarised in Table 2 below. CAP40 is a mixture of
butane, isobutane and propane.
TABLE 2 Percent by weight Example No 9 10 11 12 13 14 15 Propellant
(CAP 40) 75 75 87 80 74.1 75 87 Composition of Ex2 25 Composition
of Ex3 25 Composition of Ex4 13 Composition of Ex5 20 Composition
of Ex6 25.9 Composition of Ex7 25 Composition of Ex8 13
* * * * *